<span>The influence of solid insulation has been investigated by few researchers. The mechanism of solid breakdown is important in insulation studies. </span><span>In this research, testing on Linear-Low Density Polythylene (LLDPE) with Natural Rubber (NR) and different weight concentration of biofiller are conducted under High Voltage Direct Voltage (HVDC) by using needle and sphere types of electrode arrangements. Oil Palm Empty Fruit Bunch (OPEFB) and Pineapple Leaf Fiber (PALF) are the biofillers used for the sample</span><span>s</span><span> development. </span><span>The </span><span>LLDPE-NR samples consists of</span><span>different weight percentages of biofiller which are 0%, 2.5%. 5.0%. 7.5% and 10% </span><span>with 3mm thickness. The voltage has been increased until the breakdown occurs. Based on the results obtained, OPEFB and PALF with the highest weight percentages of 10% showed the highest damage voltages of 59.09kV and 59.36kV. It has been proven that both samples with the highest filler content have appropriate insulating properties. In conclusion, the addition of biofiber to LLDPE-NR has improved the breakdown properties compared to pure LLDPE.</span>

Photovoltaic (PV) system is recognized as one of the most current renewable energy types in producing electrical power. The theories that science explain related to the function of the sun is in accordance with what is also described in the Qur'an. There is one ayah Quran related to the Greatness of Allah and The Mercy which is “And from among His Signs are the night and the day, and the sun and the moon. Prostrate yourselves to Allah Who created them, if you (really) worship Him [Fussilat:37]. However, one of the main issues of PV system is that the performance of the system is highly dependent to environmental conditions such as weather and solar irradiance. Increases in temperature reduce the band gap of a semiconductor. The decrease in the band gap of a semiconductor with increasing temperature can be viewed as increasing the energy of the electrons in the material. The parameter most affected by an increase in temperature is the open circuit voltage. Temperature coefficient indicates how much will be the decrement in power output if PV module. Hence, it is important to predict the actual generating output power of PV systems. This study investigates the relationship between the temperatures of the PV panel with the PV power output. The PV systems installed at the rooftop of Mega label SDN. BHD. with type of poly-crystalline 405.72KWP has been chosen as the reference system in this study. The results have shown that the rise of PV panel’s temperature will make the value of the PV electrical power output decreases.